U.S. patent number 5,794,342 [Application Number 08/694,829] was granted by the patent office on 1998-08-18 for oscillating blade razor.
Invention is credited to Melville G. Davey.
United States Patent |
5,794,342 |
Davey |
August 18, 1998 |
Oscillating blade razor
Abstract
An oscillating blade razor for removing hair projecting from
skin is described. At least one cutting blade is mounted to a
shuttle which is nested within a cartridge such that the shuttle is
free to move in a longitudinal oscillating motion relative to the
cartridge. The cartridge is removably affixed to the head of the
razor in which is disposed a cantilever type bimorph piezoelectric
motor, the proximal end of which is fixedly mounted in the head
such that the distal end engages the shuttle and drives it in a
reciprocating, oscillatory motion when the cartridge is engaged
with the head and power applied. The head further incorporates the
mechanism for engaging the cartridge. In one preferred embodiment,
the cartridge incorporates electrical contact means for sensing the
end travel of the oscillating shuttle. The head is disposed on the
distal end of a handle which contains a battery, an on/off switch,
and the electronic means for driving the distal end of the
piezoelectric motor in an oscillatory motion. The proximal end of
the handle provides a means for replacing the battery.
Inventors: |
Davey; Melville G. (Swansea,
MA) |
Family
ID: |
24790433 |
Appl.
No.: |
08/694,829 |
Filed: |
August 9, 1996 |
Current U.S.
Class: |
30/45;
30/43.92 |
Current CPC
Class: |
B26B
21/38 (20130101) |
Current International
Class: |
B26B
21/08 (20060101); B26B 21/38 (20060101); B26B
021/40 () |
Field of
Search: |
;32/45,43.42,43.41,277.4 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Watts; Douglas D.
Claims
I claim:
1. A razor comprising
a cartridge comprising a case, a shuttle and, at least one cutting
blade attached to and aligned longitudinally with said shuttle,
said shuttle disposed within said case and constrained to movement
substantially in the longitudinal axis,
a head including a cartridge engaging means and a cantilever
mounted piezoelectric vane positioned such that the distal end of
said piezoelectric vane engages said shuttle when said cartridge is
engaged with said head, and
a handle attached to said head, said handle comprising a
piezoelectric vane electronic driving means, a battery for powering
said electronic driving means, and an on off switch.
2. The razor of claim 1 wherein said cartridge further comprises
means for producing an electrical signal corresponding to each end
of longitudinal travel of said shuttle and means for storing the
kinetic energy of longitudinal motion of said shuttle.
3. The cartridge of claim 2 wherein said means for storing the
kinetic energy of longitudinal motion of said shuttle comprise
spring clips attached to the inside ends of the said case
containing said shuttle and aligned with the longitudinal axis of
said shuttle such that one of said spring clips contacts a
corresponding end of said shuttle at each end of travel of said
shuttle, thereby compressing said spring clip, and said means for
producing an electrical signal corresponding to the end of
longitudinal travel of said shuttle comprise conductive means
contacting separately each face of said piezoelectric vane, said
conductive means routed to the corresponding ends of said shuttle,
and further comprising, said spring clips in an electronically
conductive relation to said cartridge engaging means, the entirety
providing an electronically complete path between alternate faces
of said piezoelectric vane and said cartridge engaging means at
each end of travel of said shuttle.
4. The cartridge of claim 3 wherein said case containing said
shuttle further comprises two or leaf springs longitudinally
separated and fixedly secured along each of the ends, respectively
to said case and to the corresponding positions along said shuttle,
the faces of said leaf springs being aligned normal to the
longitudinal axis of said shuttle, thereby providing constraint and
alignment of said shuttle within said case while allowing
longitudinal motion of said shuttle.
5. A means for driving a cutting blade in an oscillating
longitudinal motion comprising a shuttle for mounting said blade
said shuttle constrained to move substantially longitudinally
within a case and further comprising a cantilever mounted
piezoelectric vane having a proximal end fixed in relation to said
case and a distal end engaging said shuttle further comprising an
electronic means for driving said piezoelectric vane in an
oscillatory mode such that said piezoelectric vane distal end is
deflected in the longitudinal axis of said shuttle, substantially
normal to the plane of a face of said piezoelectric vane and along
a central axis connecting said proximal end and said distal
end.
6. Claim 5 further comprising an electronic end of travel, signal
producing means, in operative relation to said electronic means for
driving said piezoelectric vane, said end of travel signals causing
the electronic driving means to produce piezoelectric vane driving
signals synchronously with the motion of said shuttle.
7. Claim 5 further comprising spring means for converting the end
of travel kinetic energy of said shuttle to mechanical potential
energy, release of said mechanical potential energy occurring
naturally, synchronous with the reverse motion of said shuttle.
8. In a razor for shaving, having a vibrator means, a switch means,
and a power means, the improvement being,
a cartridge comprising a case and having disposed within, a shuttle
constrained to substantially longitudinal motion, having affixed
thereto, along the longitudinal axis, a cutting blade,
a piezoelectric vane, cantilever mounted at a proximal end without
motion relative to said case, having a distal end engaged with said
shuttle such that motion of said distal end imparts a like motion
to said shuttle, and
an electronic driving means for providing drive signals to said
piezoelectric vane.
9. The razor of claim 8, wherein said electronic driving means is
in operative relation to an end of travel signal producing means
for controlling the state of said electronic driving means
synchronously with the motion of said shuttle.
10. The razor of claim 8, further comprising energy storage means
for storing the kinetic energy of motion of said shuttle wherein
said energy storage means comprises one or more springs attached to
the inside ends of the said case containing said shuttle and
aligned with the longitudinal axis of said shuttle such that one of
said springs contacts a corresponding end of said shuttle at each
end of travel of said shuttle thereby compressing said spring.
11. The razor of claim 8, wherein said case containing said
shuttle, comprises two or more leaf springs longitudinally
separated and fixedly secured along each of their respective ends,
to said case and to the corresponding positions along said shuttle,
the faces of said leaf springs being aligned normal to the
longitudinal axis of said shuttle, thereby providing constraint and
alignment of said shuttle within said case while allowing
Longitudinal motion of said shuttle.
Description
BACKGROUND
1. Field of the Invention
The present invention relates to non cooperating blade devices for
cutting and particularly to razors for removing hair protruding
from skin of types often having disposable blades and a mechanism
for causing the blades to vibrate.
2. Description of Prior Art
It is well known to anyone having carved a turkey at Thanksgiving
dinner that some longitudinal motion of the knife is helpful in
making the cut. This phenomenon in fact has given rise to several
forms of reciprocating blade carving knives. A simplified
explanation of this effect lies in the notion that no cutting edge
is perfectly smooth nor comes to a perfect zero width. Therefore,
any cutting action of a knife is enhanced with longitudinal motion
by causing tearing and removal of material at some microscopic
level in much the way, macroscopically, a saw cuts a log.
To this end, several schemes have been devised to provide
reciprocating, vibrating, or oscillating motion to non cooperating
blade razors used for shaving. Vincent Motta, U.S. Pat. No.
5,007,169 for instance describes a razor containing a rotary motor
driven mechanism with eccentric coupling for imparting oscillatory
movement to the cartridge. Lawrence Fenn, et al, U.S. Pat. No.
4,914,816 describe a rotary motor driven razor, the motor connected
to an reciprocatory inducing weight. Steven C. Metcalf, U.S. Pat.
No. 5,299,354 describes an oscillating shaver or wet shave razor
having a rotary motor with an eccentric element for imparting
oscillating motion. While each of these inventions addresses the
problem of providing some degree of longitudinal blade motion to
enhance the cutting action, none of them meet certain empirically
determined requirements of an oscillating blade razor needed to
provide the smooth close shaving action required by the
marketplace. Each of them, for instance, impart at least some of
the vibrating motion to the skin thereby reducing the motion
imparted upon the hair. None of them are capable of the high rate
of oscillation, empirically determined by this inventor, for
effective cutting. A simple calculation demonstrates this
requirement. The nominal speed at which a user moves a razor across
the skin is of the order of 15 mm sec. It was determined that
effective cutting occurs when longitudinal motion of the cutting
edge is of the order of 10 times or greater the depth of cut.
Therefore, given that a hair diameter is of the order of 0.12 mm,
and that the longitudinal displacement of the cutting edge is of
the same order, then the longitudinal oscillatory motion of the
cutting edge should occur at least once every 0.8 milliseconds or
at the rate of 1,250 Hertz. It is further speculated that this
speed of action produces the added benefit of causing the cutting
edge to operate against the inertia of the hair, giving rise to
less compliance of the hair within the skin and therefore a more
effective cutting action against the hair. Additionally, none of
the prior art means lend themselves to the compact, low cost, light
weight, energy efficient drive mechanism that is required of an
effective oscillating blade razor.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide an
effective means of shaving protruding hair from the skin, reducing
pulling action, and providing a closer shave, by improving the
cutting action of a blade using high speed longitudinal oscillatory
motion of a non cooperating blade device.
It is a further object of the present invention to demonstrate a
high speed oscillatory means for driving a cutting blade in the
longitudinal axis.
It is a further object of the present invention to demonstrate a
means of driving a cutting edge device in a high speed oscillatory
motion for precise, delicate cutting.
A yet further object of the present invention is to provide a
battery powered oscillating blade razor which is simple, light
weight, energy efficient and adaptable to operation with disposable
cartridges.
One preferred embodiment of the present invention is a non
cooperating blade, shaving device commonly known as a wet razor. It
comprises a blade oscillating means for causing longitudinal motion
of a shuttle and its attached blade within a cartridge which is
removable from a head and the attached handle of the razor.
The oscillating means is a cantilever mounted, bimorph
piezoelectric vane, known as the motor. The term bimorph indicates
that ceramic peizoelectric material is attached to both sides of a
central vane. Single sided devices also work; just not as
effectively. The ceramic piezoelectric material is polarized such
that an applied charge causes the vane to bend along its
longitudinal axis substantially normal to the plane of the vane.
The motor is fixedly mounted at the proximal end with the plane of
the vane normal to the longitudinal axis of motion, in the head of
the razor, such that the distal end engages the shuttle when the
cartridge is engaged with the head. This equates to a cantilever
mount. A battery powered circuit consisting of an electronic flip
flop and a clock signal generating means is used to provide
suitable signals for driving the motor.
An alternate version of a first described blade cartridge is
illustrated and described to demonstrate an improved model which
may be more suitable for use in wet environments where soap and
hair could possibly interfere over time with the closer tolerances
needed for the first described cartridge. That is, the shuttle of
the first described unit is constrained to movement in the
longitudinal axis by the fit of the shuttle to a case. In the
second described cartridge the shuttle is constrained to movement
substantially in the longitudinal axis by mounting using a pair of
parallel leaf springs. In this instance the shuttle can be
substantially smaller than the case.
The above and other objects, features, aspects, and advantages of
the present invention: will become more apparent from the following
detailed description of the present invention when taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1. An isometric line drawing of a razor of the current
invention with cartridge detached.
FIG. 2A. A cross section view through the center of one preferred
embodiment of a cartridge.
FIG. 2B. A plan view from the proximal face of the cartridge of
FIG. 2A.
FIG. 3. A partially transparent line drawing of the head of one
preferred embodiment of the razor.
FIG. 4. A partially transparent line drawing of the handle of one
preferred embodiment of the razor.
FIG. 5. An electronic schematic drawing of a drive circuit for a
piezoelectric vane showing the relationship in a preferred
embodiment of the electronic driving means and the mechanical
means.
FIG. 6. A cross section and plan view of an alternate preferred
embodiment of a cartridge.
PART NUMBERS
20 Cartridge
21 Blade
22 Shuttle
23 Case
24 Slot
25 Tabs
26 Spring Clip
27 Ferrules
28 Shuttle Conductors
40 Head
41 Eject Button
42 Tines
43 Conductors
44 Enclosure Part
50 Motor
60 Handle
62 Switch
64 Battery
65 Cap
70 Drive circuit
71 Flip Flop
72 Resistor
80 Cartridge B
81 Leaf Springs
82 Shuttle B
83 Case B
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is an isometric line drawing of the razor with cartridge 20
and shuttle 22 disengaged from the head 40. Cartridge 20 is engaged
by tines 42 of head 40 through the action of eject button 41. The
motor 50 is shown with its proximal end mounted in head 40 leaving
the distal end free to engage a slot in shuttle 22 when cartridge
20 is engaged on tines 42. Handle 60 incorporates the power on off
switch 62 and electronic elements (shown in FIG. 4) and provides a
user hand grip.
FIG. 2A is a cross section view through the center of the cartridge
20. The cutting device, blade 21, is of the type generally found in
disposable razor cartridges. It is the approximate length of,
rigidly attached to, and disposed on shuttle 22 on a bias such that
it extends slightly outside the distal plane, the skin contact
surface, of cartridge 20 when assembled with case 23. The shuttle
22 is nested within case 23 and retained by tabs 25. Case 23 is
dimensioned such that shuttle 22 is constrained to move
longitudinally without restraint and substantially without movement
in either of the other two axis. Positioned at each end of case 23
is a spring clip 26. Spring clips 26 are aligned to contact shuttle
22 at the ends of travel and compress during the extreme
longitudinal excursions of the shuttle 22. Spring clips 26 are
fastened in place with ferrules 27 (shown in FIG. 2B) so as to
provide a metallic connection of spring clips 26 to the exterior
end portions of case 23. Spring clips 26 serve the dual purpose of
converting the kinetic energy of motion of shuttle 22 to stored
potential energy and of providing a conductive electrical path for
generating an "end of travel"signal. The result is an energy
efficient system for increasing the natural frequency of
oscillation of the spring mass system formed by shuttle 22 and
motor 50 (shown in FIG. 3). Shuttle 22 incorporates a slot 24
within the body for engaging the distal end of a cantilever mounted
bimorph piezoelectric motor 50. Slot 24 is configured such that the
tip of motor 50 engages the shuttle 22 along an axis formed by
connecting the center lines of ferrules 27 and substantially
without relative longitudinal motion and without restricting the
bending action of motor 50.
FIG. 2B is a plan view from the proximal plane of cartridge 20. The
shuttle 22 is nested within case 23 and held in place with tabs 25
so as to allow longitudinal motion of the shuttle 22. Conductors
28L and 28R each run from their respective sides of slot 24 to the
corresponding ends of shuttle 22 so as to make continuous metallic
contact to the respective faces of motor 50 (shown in FIG. 3) when
it is engaged in slot 24 and intermittent contact to spring clips
26 during the oscillating excursions of shuttle 22. Spring clips 26
are fastened in place with ferrules 27 so as to create a conductive
path from spring clips 26 to the outside ends of case 23 and to
tines 42 of head 40 when cartridge 20 is engageds.
FIG. 3 is a partially transparent line drawing of the head 40
portion of the razor. Enclosure parts 44 are suitably, configured,
assembled plastic molded pieces serving to secure motor 50 at the
proximal end, the tines 42 at the positions designated as "A", and
handle 60 not shown at its distal end. Tines 42 are constructed of
a metallic spring material and pivot slightly about positions "A"
in FIG. 3 when bent along the proximal edge by the action of eject
button 41. Thereby pressing on the button 41 causes tips "B" to
separate. This separation of tips "B" allows cartridge 20 to be
inserted between tips "B" and then secured to head 40 by releasing
the pressure on eject button 41 allowing tips "B" to come together
and insert into ferrules 27 of cartridge 20. Tines 42 are
constructed from a single piece of spring conductive material and
serve to create an electrical path from ferrules 27 of cartridge 20
to conductor 43-2. Tines 42 are substantially more rigid than any
spring elements in cartridge 20 thereby maintaining cartridge 20
substantially fixed in the longitudinal axis relative to the head
40 and handle 60. Opposite faces of the cantilever mounted bimorph
piezoelectric motor 50 are operationally connected to conductors
43-1 and 43-3 respectively. Conductors 43 are suitably terminated
at the proximal end of head 40 to operationally engage drive
circuitry 70 of handle 60 when handle 60 is assembled with part 44
of head 40.
FIG. 4 is a partially transparent line drawing of handle 60 of the
razor. Handle 60 is a suitably configured plastic molded piece
providing interior space for drive circuit 70 and battery 64. The
distal end of handle 60 is suitably configured to mate with part 44
of head 40 and provide operational connection between drive circuit
70 and conductors 43. Suitably located on handle 60 is a power on
off switch 62 operationally connected between one pole of battery
64 and drive circuit 70. The opposite pole of battery 64 is
operationally connected to drive circuit 70. A suitably configured
cap 65 is provided for the proximal end of handle 60 to allow
battery 64 replacement.
FIG. 5 is a schematic drawing of drive circuit 70 in operational
relation to battery 64, switch 62, tines 42, shuttle conductors 28L
and 28R, conductors 43, and motor 50. When switch 62 is closed,
power from battery 64 is applied to flip flop 71 and a pull up
resistor 72. Flip flop 71 is a standard electronic component known
in the art and is configured to change state with a failing edge
signal on the clock line. Initially when powered, the state of the
"Q" line of flip flop 71 is high (that is: at the positive supply
voltage level) and the state of the "Q" is low (that is: at the
negative supply voltage level or ground). Motor 50 always deflects
away from the positive charge face and toward the negative charge
face. Hence when initially powered via flip flop 71, motor 50
deflects to the right (per the right arrow in FIG. 5) causing
shuttle 22 and attached shuttle conductors 28 to travel to the
right. At the extreme end of travel, shuttle conductor 28R contacts
the right end spring clip 26 which via the right end ferrule 27 and
tines 42 completes an electrical circuit to ground through the
right (low) face of motor 50. This circuit completion causes the
initially high clock line of flip flop 71, as pulled up by resistor
72, to go low causing flip flop 71 to change state. The state
change causes motor 50 to deflect to the left moving shuttle 22
left and breaking the completed circuit formed via conductor 22R
allowing the clock line to go high. When shuttle 22 reaches the
extreme left end of travel, shuttle conductor 28L contacts the left
end spring clip 26 which via the left end ferrule 27 and tines 42
completes a circuit to ground through the left (now the low) face
of motor 50. This circuit completion causes the high clock line of
flip flop 71, as pulled up by resistor 72, to go low causing flip
flop 71 to change state. The state change causes motor 50 to
deflect to the right moving shuttle 22 right and breaking the
completed circuit formed via conductor 22L allowing the clock line
to go high. The shuttle 22 continues to move right until the right
side circuit is once again established causing the clock line to go
low and once again causing flip flop 71 to change state. In this
way, the end of travel signal remains synchronous with the motion
of the shuttle 22. This repetitive process continues as long as
power is applied through switch 62 resulting in the longitudinal
oscillation of shuttle 22 and the attached blade 21
FIG. 6 is a plan view from the proximal plane of cartridge B 80 and
section view of cartridge B 80. Cartridge B 80 is an alternate
version of cartridge 20 in which shuttle 22 is replaced by the
shuttle B 82 and case 23 is replaced by the case B 83. Shuttle B 82
is disposed within case B 83 and held in place with leaf springs 81
so as to allow longitudinal motion of the shuttle B 82. Conductors
28 each run from their respective sides of slot 24 to the
corresponding ends of shuttle B 82 so as to make continuous
metallic contact to the respective faces of motor 50 (shown in FIG.
3) when it is engaged in slot 24 and intermittent contact to spring
clips 26 during the oscillating excursions of shuttle B 82. Spring
clips 26 are fastened in place with ferrules 27 so as to create a
conductive path from spring clips 26 to the outside ends of case B
83 and to tines 42 of head 40 when cartridge 20 is engaged. Leaf
springs 81 are longitudinally separated and fixedly secured along
each end of the springs 81 to case B 83 and the corresponding
positions in shuttle B 82 respectively. The faces of the springs 81
are aligned normal to the longitudinal axis of shuttle B 82. The
springs 81 are rectangular in shape and can be constructed of any
suitable spring material. Additionally, while the springs 81 are
shown as individual entities, they can be constructed in plastic as
integral parts of case B 83 and shuttle B 82 by a molding
process.
While the above description has been made mainly with reference to
a razor of the type normally used in shaving, the present invention
is also applicable to other cutting instruments such as surgical
knives and similar delicate cutting devices. It, for instance,
would be a natural variation of the above described invention to
extend the blade longitudinally beyond the end of the shuttle and
cartridge and reconfigure the head and handle to lie parallel to
the longitudinal axis of the blade there-by producing a type of
scalpel.
Although the present invention has been described and illustrated
in detail, it is clearly understood that the same is by way of
illustration and example only and is not to be taken by way of
limitation, the spirit and scope of the present invention being
limited only by the terms of the appended claims. CLAIMS
* * * * *